This invention relates to a paper-plastic laminate packaging material and a paper-plastic-paper laminate packaging material in the form of sheeting which is capable of being converted into a self-closing package. These materials include a layer of cohesive on one side to enable the material to be self adhering after being placed around or about an item to be packaged.
In the past, both paper-plastic laminate sheeting and cohesives have been developed. U.S. Pat. No. 5,244,702 discloses a paper-plastic laminate sheeting capable of being converted by conventional equipment into envelopes, grocery bags and other dilatable container products that are initially in a flat state. This patent describes a paper-plastic laminate sheeting in which a facing paper sheet is cold-laminated to a reinforcing film of synthetic oriented plastic material, whereby the properties of the oriented film are unimpaired and the products made therefrom have exceptional strength tear and burst characteristics. U.S. Pat. No. 5,780,150 discloses a sealing tape constituted by a paper-plastic laminate for sealing a carton or other article formed of recyclable material.
The use of cohesive materials in product packaging are generally known in the art. U.S. Pat. No. 6,076,969 issued to Jaisle et al. discloses a product package having a re-sealable closure employing a cohesive and a pressure-sensitive adhesive for reseal capability. U.S. Pat. No. 5,655,707 to Jensen discloses a paperboard container fashioned from a unitary blank which is precut and pre-scored to yield desirable fold lines, with the top of the container being provided with a pair of upstanding flanges having a strip of cohesive material so that the two upper flanges are secured together by virtue of the cohesive material on each.
There is a large increase in the mailing of packages due to catalog sales, sales over the internet and other fulfillment houses. Most of these packages are of heavy paper or cardboard construction. Such constructions are convenient, provided in different sizes and are of low cost, but these constructions are not resistant to moisture in the form of snow, rain or other forms of water. The increased number of packages to be shipped creates a need for new and improved, flexible packaging materials that can be used to accommodate different sizes of such packages as well as to protect such packages from adverse weather conditions during shipment. The present invention now provides such a material.
In accordance with the present invention, a new packaging material in the form of a unitary laminate sheeting has been developed. The laminate sheeting is flexible, tough, and water impermeable and is capable of enclosing an article within a formed pocket.
Advantageously, the novel packaging material of the present invention provides the ability to achieve outstanding printed graphics thereon, based on the selection of paper for the paper ply component of the packaging material.
The packaging material generally includes a paper layer and a water impermeable plastic film layer having a first corona discharge treated surface. The first corona-discharge treated surface is adhesively laminated to the paper layer to form a paper-plastic film laminate having first and second opposed outer surfaces. The packaging material additionally includes a layer of cohesive coating on at least a portion of one of the first and second outer surfaces. The cohesive material of the invention has the property of sticking only to itself. Thus, when an article or object is placed on the cohesive coated surface of the laminate sheeting, the sheeting can be folded over the article or object and when the opposing cohesive coated surfaces come into contact with each other, they form a cohesivexe2x80x94cohesive bond thereby enclosing the article within a formed pocket. Since the cohesive has the property of only sticking to itself, the coated surface does not stick to the article or object within the package. The layer of cohesive material may be applied to the outer surface of the paper layer or the plastic film layer of the packaging material.
In another embodiment, the packaging material comprises a three ply, paper-plastic-paper laminate sheeting. The plastic film has a second corona discharge treated surface opposite the first corona discharge treated surface, wherein the second corona-discharge surface is adhesively cold laminated to the second paper layer, thereby producing a three ply laminate sheeting having a first and second outer surfaces of paper with the cohesive material coating applied onto one of the outer surfaces of paper.
Generally, the paper layer has a thickness of from about 3 to 6 mils, while the plastic film layer has a thickness of from at least about 0.5 to about 3 mils. The plastic film component typically comprises a polymer selected from the group consisting of polypropylene, polyethylene and polyester, while the paper layer may be coated paper, Kraft paper, or higher quality paper such as Bond or white paper. The paper layer may be metallized to obtain a decorative packaging material. The metallized paper layer may also be provided with graphics thereon. Also, the plastic film component of the packaging material may be oriented or biaxially oriented to impart high-strength thereto, and is cold laminated to the paper ply so that lamination is effected without heat that would impair the orientation and strength of the plastic film ply.
The above described packaging material is capable of achieving outstanding printed graphic thereon so that if desired, the exterior of the package may exhibit logos, trademarks, emblems and other hallmarks.
Depending on the resultant package desired, the packaging material may comprise a plastic film layer as the outer surface layer of the package thereby constituting a water-impermeable package. The outer surface of the plastic layer may be corona discharge treated to render it receptive to inks and printing. Alternatively, the packaging material may comprise a paper layer as the outer surface layer of the package and a plastic film layer as the inner surface of the package. Further, the printable paper layer may comprise the inner layer of the package, wherein the printed outer surface of the paper layer may be exposed through a transparent plastic layer, which forms the exterior of the package and is cold laminated to the printed surface of the paper layer. Thus, the printed surface of the paper layer is legible through the transparent plastic film and the paper layer itself is protected from rain, snow, or any other water elements by the water-resistant plastic film layer.